#343 Improved border processing in denoise filter

galenframework · Nov 14, 2015 · eb6fb05 · eb6fb05
1 parent 28cd9d8
commit eb6fb05
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Showing 2 changed files with 11 additions and 3 deletions.
diff --git a/galen-rainbow4j/src/main/java/com/galenframework/rainbow4j/filters/DenoiseFilter.java b/galen-rainbow4j/src/main/java/com/galenframework/rainbow4j/filters/DenoiseFilter.java
@@ -30,12 +30,15 @@ public DenoiseFilter(int radius) {
     public void apply(byte[] bytes, int width, int height, Rectangle area) {
         radius = Math.min(radius, Math.min(width / 2, height / 2));
 
+        int maximumPossiblePixels = (radius * 2 + 1) * (radius * 2 + 1);
+
         if (radius > 0) {
             for (int yc = 0; yc < height; yc++) {
                 for (int xc = 0; xc < width; xc++) {
 
                     int blackPixels = 0;
                     int whitePixels = 0;
+                    int total = 0;
 
                     int startY = Math.max(yc - radius, 0);
                     int startX = Math.max(xc - radius, 0);
@@ -55,12 +58,18 @@ public void apply(byte[] bytes, int width, int height, Rectangle area) {
                             else {
                                 whitePixels ++;
                             }
+
+                            total++;
                         }
                     }
 
+                    double amountRatio = ((double) total) / ((double) maximumPossiblePixels);
+
                     int k = yc * width * ImageHandler.BLOCK_SIZE + xc * ImageHandler.BLOCK_SIZE;
                     if (whitePixels > 0) {
-                        if (blackPixels / whitePixels > 3) {
+                        if ((amountRatio > 0.6 && blackPixels / whitePixels > 3) // matching normal pixels
+                            || (amountRatio <= 0.6 && blackPixels / whitePixels >= 2) // matching pixels that are on border
+                                ) {
                             bytes[k] = 0;
                             bytes[k + 1] = 0;
                             bytes[k + 2] = 0;

diff --git a/galen-rainbow4j/src/test/java/com/galenframework/rainbow4j/tests/Rainbow4JTest.java b/galen-rainbow4j/src/test/java/com/galenframework/rainbow4j/tests/Rainbow4JTest.java
@@ -395,10 +395,9 @@ public void shouldApply_denoiseFilter_andRemoveAllNoisePixels() throws IOExcepti
         }
 
         List<Integer> expectedPixels = asList(
-                840, 545, 537, 536, 543, 524, 526, 428, 432
+                840, 534, 531, 536, 543, 524, 526, 428, 432
         );
 
-        // Assert that denoise 1 removes only some of them
         for (int size = 1; size < 10; size++) {
             ComparisonOptions options = new ComparisonOptions();
             options.setTolerance(25);